The present invention relates to improvements in skives used, for example, for stripping a copy sheet from a hot fuser roller in electrographic apparatus.
Skives comprising elongate fingers have been used for stripping sheet-like members from rollers in apparatus of various types. More specifically, skives have been used for deflecting copy sheets from hot fuser rollers in electrographic apparatus. The fuser rollers in such apparatus commonly have a soft, flexibly outer surface that is flexed as the copy sheet passes through the nip between a fuser roller and a back-up roller or between two such fuser rollers. This soft surface can be damaged by the skive fingers. Damage to the fuser roller can occur, for example, if the sheet leaving the nip between the rollers causes the skive finger to deflect in a direction which urges the tip end of the skive finger into the soft surface of the fuser roller, thereby gouging the roller surface.
Various attempts have been made to avoid the problem of a skive gouging a soft fuser roller. For example, in U.S. Pat. No. 4,336,992, issued on June 29, 1982 in the names of Szluch et al, skive fingers are provided which are sufficiently flexible so that they can be deflected entirely out of contact with the fuser rollers. The fingers can rotate 360 degrees and return to their operating position.
In other known skiving apparatus weights or springs are used to urge the tip end of the skive or sheet stripper into engagement with a rotating roller. Apparatus of this type is disclosed in U.S. Pat. Nos. 3,885,786 and 3,992,000.
In spite of the many efforts to provide satisfactory skives, the gouging problem persits, and results in expensive repair or replacement of the fuser roller and the skive itself. In addition, some prior skives are complex in construction and thus expensive to manufacture. Also, some known skives require accurate adjustment of weights, springs or other elements during assembly, or in order to maintain the required relationship between the skive and fuser roller. Accordingly, there is a continuing need for an improved skive which will not gouge a fuser roller, and which is inexpensive, easy to install and simple to replace.